diff --git a/exposed/DOC.txt b/exposed/DOC.txt
index 021edf99..c1665097 100644
--- a/exposed/DOC.txt
+++ b/exposed/DOC.txt
@@ -350,7 +350,10 @@ SLVS_C_AT_MIDPOINT*
 SLVS_C_HORIZONTAL
 SLVS_C_VERTICAL**
 
-    The line connecting points ptA and ptB is horizontal or vertical.
+    The line connecting points ptA and ptB is horizontal or vertical. Or,
+    the line segment entityA is horizontal or vertical. If points are
+    specified then the line segment should be left zero, and if a line
+    is specified then the points should be left zero.
 
 SLVS_C_DIAMETER
 
diff --git a/exposed/example.c b/exposed/example.c
index 5c6cccd0..ef1d53fd 100644
--- a/exposed/example.c
+++ b/exposed/example.c
@@ -102,7 +102,7 @@ void Example2d(void)
     sys.param[sys.params++] = Slvs_MakeParam(5, g, qx);
     sys.param[sys.params++] = Slvs_MakeParam(6, g, qy);
     sys.param[sys.params++] = Slvs_MakeParam(7, g, qz);
-    sys.entity[sys.entities++] = Slvs_MakeNormal3d(102, g, 3, 4, 5, 6);
+    sys.entity[sys.entities++] = Slvs_MakeNormal3d(102, g, 4, 5, 6, 7);
 
     sys.entity[sys.entities++] = Slvs_MakeWorkplane(200, g, 101, 102);